We will develop a new platform for an aptamer based binding assay that will be utilized in the development of a quick, simple, non-isotopic homogeneous assay for analytes of clinical interest. The incorporation of peptide aptamer technology into this assay will alleviate many of the problems that are commonly encountered with immunoglobulin based binding assays. First, peptide aptamers directed against any protein analyte are much easier and cheaper to isolate than are immunoglobulins. Second, the size of the aptamer platform is relatively small which facilitates rapid kinetics. Third, there will not be human antibodies to the aptamer present in samples to interfere with the assays. Finally, the detection system will be spectrophotometric. Furthermore, the amino acid sequence of the aptamer will be known and reproducible, thus providing long term consistency to any assays developed with this technology. These features will provide broad applicability to the assays as they will be quick and simple to perform on a wide range of the common routine clinical chemistry analyzers. Thus, both labor and capital costs will be decreased while providing an accurate, precise and environmentally friendly test result. PROPOSED COMMERCIAL APPLICATION: Clinical Diagnostics.